Process of making steel die-punches.



A. J. BRADLEY.

PROCESS OF MAKING STEEL DIE PUNGHBS.

APPLICATION MLPD JULY 14, 191s..

1,1 18,180', Patented Nov. 24, 1914.

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\ nunlmliunlllll In IIIII@ In HINIIlIIl lI nl "um lll "Immlu 3 A' HQI IImmun EW um 5f l II IMI l llllllllllizlmlllllliIIII l m||||||9ll||||||||To all whom t'my concern) j Be it known Ithat I, vANDREW J. BRADLEY, acitizen of .the United States, and a {resii dent of the cityoNeW Yorkand' State ofl New York, have invented a new and usefull ImprovementinProcesses of Making Steel' Die-Punches, ofwhich the followingis aspecification.

This invention relates to steel dies and:

punches such asare'used in stencil cutting"7 machines, and to the art of'making' the same and 'comp-rises certain improvements in the dies andprocesses described i'n my prior Patents Nos. 522953 and 613236.

Punches for stencil machines should have bodies with arallelfwallsexactly conforming to the siiape of their faces. A punch body withparallel walls will not stretch the uncutpaper `surrounding the portionscut out thereby during the punching stroke, as might. occur if the punchbody was tapered toward the face of the unch, and also a parallel walledpunch wil `not catch under the edges of the hole on the returni strokeasmight occur if the punch body was upset or. enlarged upon its face.

Dies for stencil machines should be a i'ew thousandths of an inch largerthan the faces of the punches mating therewith, iand moreover, theopeningy through the die should be ared or. slightly enlarged toward thebottom of the die in order to provide a clearance for the punched outieces ofthe stencil and allow themy to all through readily. i

The object of this invention is to produce interchangeable dies andpunches having certain advantages hereinafter set Jforth.

A further object is to devise-an improved process of manufacturing saiddies which requires no hand ling or upsetting to insure exactconformation and'proper clear-v ance of the cutting edges. Thisinvention consists in the dies and punches, and in theV process ofmaking the same, hereinafter described. i

No. claim is made herein for the diesl and punchesthis part of the.invention being reserved for a separate patent:

In the accompanying drawings, 1n whlch` like characters. are used l todesignate the'V same parts in the several views. Figure' lis :"VAND'BEWJ. BRADLEY,

PATENT oFFIoE.

ois*l NEwi'Yon'K, N. Y.

l Pnlocnss :on Mammev STEEL Drs-PUNCHES.-

` Specdoationofletters Patent. Patented NOV'. 24,' 1914;.Y .,lnppuogminea vJuly i4", 191s. sena; No. 778,889;

2 3 in-Fig. 1, looklng in t e direction of' the arrows; Fig. 4 is a planView of the die blank following the punching operation, showing the sidewhich is uppermost in 'the punching dies; F igs. 5 and .6 are verticaltransverse sections through the die blankl shown in Fig. 4, on the lines5 5 and 6*-6;

r respectively; Fig; 7 Ais a top plan view of the.

die blank reversed to bring 1t into the position in which it isassembled with the punch v plate; Fig, 8 is a vertical transversevsection of the same on the line 8-.8 in Fig; 7; Fig. 9 is a top planview of the punch plate prior to assemblingwith the die blank; Fig. 10is a vertical transverse section of the same on the linelO-lO'in Fig. 9;Fig. 11 is a y transverse sectional view of the punch-plate superposedupon/ the die-blank priorto the welding operation ;Fig. 12 is a viewsimilar to Fig. 11 showing the punch plate and dieblank after thewelding operatlon, but prior to separation of the punchings or countersfrom the die-blank; Figs. 13' and 14 are transverse sectionalv views ofthe welded4 punch plate, and the die blankafter separation of thecounters therefrom, respectively; Fig. 15 isa bottom plan view of thefinished punch; Fig'. 16 is a to plan view of the inished die; and Fig.1 is a side elevation of the ini'shedlpunch and die, showing the mannerin which they are mounted in al stencil cuttngmachine.v

The drawings illustrate `the master dies for shaping, the die-blank andthe several stages in the. production therefrom of a stencil. punch anddie for cutting the letter G. A full set of master punchesand dies,comprising all the letters of the lalphabet and theusual punctuationmarks and characters, together with the numeral figures 2 to 9inclusive, is necessary to the carrying out of this process.v The diesare made with the character reverse in plan view, as shown in Fig. 1, inwhich the master die 11 for the letter G. is shown. The master dies alsohave three holes12 which coperate with 'pins (not shown) removablymounted'in thev i misuse master' punch blocks 13 for punching threetions 15 of the side walls 14 are parallel for about one thirty-secondof an inch down from the cutting edges thereof. The master punches 16are tapered slightly toward the cutting edges, their side walls 17approaching each other at the rate of about one thirty-second of an inchper inch. The lower portions 18 of the side walls 17 are arallel forabout one thirty-second of an inch up from their cutting edges. V

The process followed in making the stencil punches and dies is asfollows: A steel die .blank 21, about" three sixteenths of an inchthick, is placed on the master die and the punch brought down until ithas penetrated about four fifths through the die blank, which issuilicient to completely sever the punchings 22 from the die blank, butleave them sticking therein. At the same stroke the pins in the masterpunch lining up with the holes 12 are forced partly through the dieblank, but to a slightly less extent than the punchings the lower endsof the pins being set slightly above the face of the punch. The lowerends of the posts 23 which are raised on the under face of the die blankby the pins on the punch block are about one thirty-second of an inchabove the lower faces of the punchings 22.

The top edges of the holes punched in the I die blank are left slightlyrounded by the punch instead of having absolutely square corners. It isimpossible 'to punch soft steel and get absolutely square corners on thetop .edges of the punched holes due to the metal surrounding the hole.flowing slightly under the pressure brought upon it by the punch.Heretofore, in making stencil dies by master dies having the charactercut upright instead of inverted, it has been necessary to grind off thetop surface of the die blank in order to .get square corners for thecutting edges of the stencil die made therefrom. In this process, thebottom of the die blank becomes the top of the stencil die, and therounded corners made b v the punch are of advantage in providing bottomclearance in the holes additional to that made by the tapered side wallsof the punch. For a similar reason to that causing the top edges of theholes to be slightly rounded, the bottom edges of the punchings 22 areslightly rounded. The punchings, however, have parallel walls exactlycon` forming in size to the holes in the master die through which theyare forced, instead of being tapered like the punch. 'lhe lower edges ofthe holes in the die-blnnk, on the other hand, are slightly smaller thanthe holes in the master die, due to slight contraction after thewithdrawal of the punch, and grip the punchings tightly.

The die-blank 2l. is turned over, as shown in 7, and a punch plate 24.is placed on it, with the punched out holes 25 fitting the punchings 22.The punch plate is made with the same master dies I11 and 13 with whichthe die blank was formed, but before punching the lpunclrplate thepunch,

pins are removed, and in punching the punch is forced entirely throughthe plate.

The tapered punch bcvelsthe side walls of the holes 25 slightly. theholes being slightly wider on the side from which the punch approaches.This is the loweil side of the punch plate as shown in Figs. 9 and 10.'lhe clearance between the rounded edges of the holes in the punch plateand the rounded edges of the punchings 22 is sufficient to enable thetwo plates to be assembled one on the other as shown in Fig. 11, but notsufficient to leave any appreciable space between the meeting corners,and accordingly the punch plateserves as a ternplet for assisting inmaintaining the proper alinement of the punehings during the followingoperation. The posts 23 serve to position the punch plate parallel withthe die-blank, and insure that the depth towhich the pu-nchings projectinto the holes in the punch plate shall be uniform.

The punch plate and die-blank are clamped in assembled position, andmolten steel of the same composition as the punch plate is poured intothe cavities in the latter over the punchings 22. This molten steelfuses the punchings to the punch plate and forms a solid punch 26. asshown in Fig. 12. The operation is performed quickly. and the punchplate. and die-blank are so massive in proportion to the molten metalthat they are not much distorted by heat transferred to l,them duringthe operation. More over, if there is slight distortion of the punchplate it does not affect the alinement of the punchings, which aresecurelyy held by both the punch plate and die-blank- After the partsvcool, the punch plate and punchings are separated from the dieblank, andthe surplus metal from the welding operation is planed or ground ofi'from the back of the punch plate. which then appears as shown in Fig.13.

The die-blank is placed on the master die and lined up by the pins 23.The master punch is forced through the die-blank stencil cuttingmachine.

fcuie manner.

trim u the cuttin ed s and 've a` slight-.1.- ,ta er opi' relief tote'sf's of tlg; holes, faind ho es 27 are simultaneously punched'for thescrews 28 which attach it tothebase plate 29 of the stencil- "cuttinglmachine. rI `he edges of the die-blank are trimmed-up,`the screw holes27 are counter sunk on the to side, and the die-blank is -casehardeneforming the nished stencil die 30, as shown in Figs-ie and 17.-

The punch plate is trimmed around its edges and drilled with two holes3l which are counterbored on the side adjacent the punches for thescrews 32 which secure the punch plate to the punch block 33 of theAfter mounting the punch plate, the punch is forced through the hardenedstencil die, which shaves off -the edges of the punch walls to fit thecutting edges of the die exactly. The punch may be left soft, if onlypaper stencils are to be cut.

It is to be noted that 'the above described process produces punches anddies having sharp cutting edges exactly conforming to each other withouthand filing, and without grinding ofr the cutting faces; obviously, thepunch portions coperating with the die are exact counterparts of theholes in the latter because both are made with the same master dies.Moreover, as the dies are made from the same master dies as the punchesand as a part of the operation of making the punches, the process ischeaper and more rapid than processes wherein separate sets of masterdies are used for shaping the punches and dies, respectively.

It is evident that the sizes, shapes and thicknesses of the severalparts, and the materials used, may be changed without affecting theprocess. It is also evident that the die-blank may be punched clearthrough at the l.first stroke of'the die, and the punchings reinsertedtherein or assembled in a sepa-rate templet for holding them properlvduring theoperation of welding them to the punch plate. Moreover, thepunchings may be secured to the punch plateby welding, brazing,soldering, or any other inethod which will unite the parts in a se- Thisinvention is not limited to the exact number or sequence of operationsdescribed as constituting the preferred process `of making my improvedstencil dies.

What I claim is:

1.* The process of making'stencil character punches which consists inpunching a die-blank with a master punch conforming to a stencilcharacter, thereby shearing punchings therefrom corresponding to saidcharacter, punching a punch plate with said master punch, inverting andpartly-inserting the punchings from said die-blank in acter puncheswhich consists in fpunchin aI die-blank with -a master punch confrininto ai stencil 'character',fpunc`l`iing"apunc plate with saidmaster'puncli,inverting said punch plate andi-insertingthereinm-therounded facesof the. punchings fromvsa id die-blank, and' securingVsaid* piifchln'gstd thepunch plate.

3. The process of making stencil character punches which consists inpunching a die-blank with a master punch conforming to a stencilcharacter, thereby producing punchings having rounded lower faces,punching a punch plate with said master punch, the upper edges of theopenings in said punch plate having rounded edges, inserting saidpunchings in the openings in said punch plate with the rounded edgestoward' each other, and securing said punchings to said punch plate..

4. The process of making stencil character punches which consists inpunching a die-blank with a master punch conforming to a stencilcharacter, thereby producing punchings having rounded lower faces,

punching a punch plate with said master punch, the upper edges of theopenings in said punch plate having rounded edges, inserting saidpunchings in the openings-.in

said punch plate with the rounded edges toward each other, and securingsaid punchings to said punch plate while holding said punchings in atemplet on the side opposite said punch plate.

5. The process of making stencil; character punches which consists inpunching al die-blank with a .master punch having a' body which taperstoward its cutting edges, said body and cutting edges conforming inoutline to a stencilv character, thereby producing punchings, punching apunch plate with said master punch, inserting said punchings in thewider ends of the openings in said punch plate, and securing saidpunchings to said punch plate.

6. The process of forming mating punches sharp cutting edges u@ Lumen apunch plate with said master unch, inhardened die-blank, therebyformingsherp serting the projecting faces or' t e punchcutting edges onsaid punch and die. lo ings in said die-blank into the openings inSigned at the city of New York, N. Y., said punch plate, securing saidpunchings to this 9th dey of July, 1913.

said punch plate, removing the punchings ANDREW J. BRADLEY.

from said die-blank and forcing seidmaster Witnesses: v punch throughit, hardening said de-b1ank, FRANK J. DUFFY,

and forcing said punchings through said MARTHA NOMMENSON.

